1. Field of the Invention
The present invention generally relates to a method of treatment of plants. More particularly, the invention relates to an improved method of delivery of plant nutrients.
2. Background of the Prior Art
The supply and absorption of chemical compounds needed for growth and metabolism may be defined as nutrition and the chemical compounds required by an organism termed nutrients. The mechanisms by which nutrients are converted to cellular material or used for energetic purposes are metabolic processes. The term `metabolism` encompasses the various reactions occurring in a living cell in order to maintain life and growth. Nutrition and metabolism are thus very closely interreleted.
The essential nutrients required by green plants are exclusively of inorganic nature. In this respect green plants differ fundamentally from man, animals and a number of microorganisms, which additionally need organic compounds as foodstuffs. An essential element may be defined as one which is required for the normal life cycle of an organism and whose functions can not be substituted by other chemical compounds. In addition, the element must be shown to be directly involved in nutrition, as for example as a constituent of an essential enzyme system. Based on this definition, the following chemical elements are now known to be essential for higher plants:
______________________________________ Carbon C Potassium K Zinc Zn Hydrogen H Calcium Ca Molybdenum Mo Oxygen O Magnesium Mg Boron B Nitrogen N Iron Fe Chlorine Cl Phosphorus P Manganese Mn Sodium Na Sulphur S Copper Cu Silicon Si Cobalt Co ______________________________________
The list of essential elements shown above may well not be complete and other elements, in very low concentrations, may yet be shown to be essential for higher plants. For some microorganisms, for example, vanadium (V) has now been established as an essential element.
The plant nutrients may be divided into macronutrients and micronutrients. Macronutrients are found and needed in plants in relatively higher amounts than micronutrients. The plant tissue content of the macronutrient N, for example is over a thousand times greater than the content of the micronutrient Zn. Following this classification based on the element content in plant material, the following elements may be defined as macronutrients: C, H, O, N, P, S, K, Ca, Mg, Na and Si. The micronutrients are: Fe, Mn, Cu, Zn, Mo, B and Cl. This division of the plant nutrients into macro- and micronutrients is somewhat arbitrary and in many cases differences between the contents of macronutrients and micronutrients are considerably lower than the example cited above.
The process of nutrient uptake and assimilation by plants is not fully understood, although a number of theories of ion uptake and transport are known, see for example, Mengel et al, Principles of Plant Nutrition, Chapter 3, "Nutrient Uptake and Assimilation", International Potash Institute, Bern (1978).